Locomotive grid screening



March 25, 1930. H. E. GILLETTE LOCOMOTIVE GRID SCREENING- Filed July 15,1927 2 Sheets-Sheet 1 m 2 M v a a ,H Tdri March 25, 1930. H. E. GILLETTELOCOMOTIVE GRID S CREEN'ING Filed July 15, 1927 2 Sheets-Sheet 2Even/{or 21131 E. fi'lylelie Attorne Patented Mar. 25, 1930v UNETEE A PNT OFFICE HARRY E. GILLETTE, 0F LINCOLN, N EBBA$KA tocomorlvn e311)scnnnnme Application filed July 13, 1927. Serial No. 205,114.

This invention relates to screeninggases containing solid matter, andhas for its object the limiting or ,restricting'the size of solid matterwhich is permitted to passthrough the screening, and has for its furtherobject to provide a screen which will permit of. a certain amount ofabrasion withoutincreasing the s1ze of the openingin the screening, andfurthermore, to provide such a screening in which the componentpartshave great strength to resist external stresses without distortion suchas would increase the size of the screen openings and defeat. the objectof the screening. My device will stand up in service a relativelylongtime,

thus reducing the replacement cost and the time thelocomotive is out ofservice during'such replacesmoke stack to screen thejgases ment.

This invention relates particularly to coal burning railway locomotivesand especially to the screening. used in the front end of suchlocomotives between the lines and the of inflam mable cinders and othermaterial infiuid suspension before theyv are-thrown out of the smokestack, thereby preventing hot cinders from causing fires along theright-of-way. These grid-screens are positioned substantially transversetothe direction of the flow of the gases. g It is customary to use awoven wire netting for such screening. comprising interwoven wiresnormal to eachother and my de vice is an improvement thereon and hasforits object a construction which increases the resistance of thescreening to the physical destruction (abrasion) caused by the severe impact of the cinders and solid content in the gases, and has for itsfurther object to in crease the resistance of the screening to thechemical action of the the screening. I

These and other objects are obtained by the specific and particulararrangement of i the bars comprising the grid, which arrangementgaseswhich destroy of bars produces the minimum retarding effeet on thepassage therethrough of fluids having solids in suspension witha maximumtot-a1 screen opening consistent with the kind of coal being burned forheating.

I In the drawings:

Fig. 1 shows a typical front end of a railwaylocomotive with my deviceapplied there- 1n. I

Fig. 2 is a perspective view of my grid 5. screen. r j

Fig. 3 shows one of the grid bars.

Fig. 4 shows one of the other grid bars.

Fig. 5 shows one of the supporting bars.

Fig. 6 is a cross section of my grid.

,Fig. lshows a typical front end of a-locomotive and the usual parts,such as fiues 1; front flue sheet 2; baffle plate 3; pivoted damper 4;exhaust nozzle 5; diaphragm plate 6; grid screen 7 smoke stack 8 andsmoke box barrel 9. Y

The gases and cinders emerge from the flues 1 and pass through the opendamper 4: into chamber 1.1,whileother gases andcinders emerge fromthe'flues 10 into the chamher 11. All of these gases and cinders passbelow the adjustable diaphragm plate 6 and thence through the screen 7and out the smoke stack8.@, l 1

These gases attain a velocity of about 1800 feet per second, whichcauses a terrific impact between particles of cinders,etc.-, in thegases and the screeningcausing friction and conseting with agrid-whichcomprisesa series of substantially parallel grid bars spacedequidistance apart and positioned with the width of the bar parallel tothe line of force of the moving gases sothat this gridbar has greatstrength to resist the bending forces caused by the moving gases andalso will permit of considerable abrasion without increasing the size ofthe openings for the gases. Positionin g these grid bars in the mannerdescribed also has the advantage that a considerable portion of them canbe eaten away by the chemical action of the gases without increasing thesize of the opening for the gases.

By positioning' the grid bars with their width parallel to the directionof the moving gases-increases their strength as beams so that theirsupports may be placed further apart than in the caseof a woven'wirenetting,

therefore, I position the supporting bars considerably further apartthan the grid bars. Another object of the invention is to obtain a verystrong grating to resist forces normal to it and at the same time toobtain a large total area of opening for the flow of gases and yet havea very small maximum width of opening. Bars may be positioned so as toform square instead of rectangular openings.

It may be advisable to form the supporting bars of thicker material thanthe grid bar which construction would require fewer sup porting barspermitting them to be spaced further apart.

My improved construction comprises a plurality of spaced apart grid bars29, 30, each having a thickness .T which, for comparative purposes, areequal to the width 1) of the above mentioned wires and are spaced apartdistances Aequal to the distance between the wires of the abovementioned netting. The supporting bars 31 are preferably spaced apartseveral times the distance between the grid bars and are preferablywider than the grid bars. The upper grid bars 29, Fig. 4 are unnotchedand have a top edge 29 and a bottom e lge 29". The lower grid bars 30,Fig. 3 have a top edge 30 and a bottom edge 3O and spaced notches 30 inthe top edge. The supporting bars 31, Fig. 5 have top edge 31 and bottomedge 31 and upper spaced notches 31' in its top edge and spaced notches31 in its bottom edge, these notches being arranged in staggeredrelation to each other. The grid bars 29 are of a depth equal to thedepth of the notches 31' and, therefore, when assembled with thenotches, Fig. 2, the top edge 29 of the grid bars 29 are level with thetop edge 31 of the supporting bars 31. The notches-30 in the grid bars30 and the notches 31 in the supporting bars are proportioned to permitthe bars 30 when assembled in the supporting bars 31 to lie in a planebeneath the top edge of the grid bars 29 and flush with'the bottom edge31 of the supporting bars 31.

In other words, as shown in Figure 2, the grid screen comprisessupporting bars having alternate grid bars 29 and 30 supported there--in, the grid bars 29 being at a higher level than the supportingbars onone side of the grid and being at a lower level than the supporting barson the other side of the grid, as shown by Figure 2 and in cross sectionby Figure 6. In having the supporting bars 31 and thegrid .bars 30notched as heretofore described, the grid is easily assembled and doesaway with the objectionable features in priorconstructions whereinmembers are in terwoven with each other or are connected to each otherby means of enclosed openings or slots in the members. In assemblin thegrid screening, it is only necessary to place the supporting bars 31 inthe proper position. insert the grid bars 29 in the notches 31 andsponding to then insert the notches 30 of the grid bars 30 in thenotches 31 of the supporting bars 31 and to drive the bars into tightengagement with each other or to weld the grid bars to the supportingbars. After this assemblage is completed it is only necessary to placethe grid screen in its proper position in the smoke box, as shown byFigure 1, and an efficient screening of the solids is affected, as hasbeen proven in a number of severe practical tests.

he grid bars and supporting bars are substantially rectangular but maybe tapered and/or with rounded corners and each bar is positioned withits width V, Y normal to the plane of the grating. The grid bars andsupporting bars are secured together in any convenient manner such as bypressure or welding. lhe grid bars 30 are staggered rela- 'tive to eachother so as to provide an overlap- C or throat; that 1s, certain of pingportion said bars are spaced below and between the other bars so thatthe adjacent bars have only a partially'overlapped relation. In theconstruction illustrated the alternate bars are spaced below and betweenthe bars therebetween.

When the gases pass through the netting or grid they are necessarilycompressed which offers a certain amount of resistance and the 7 smalleramount of time (or space) these gases "are held in compression the lessresistance there is and lesser frictional abrasion of the grid bars. Inthe construction shown this compression space is only equal to theoverlapping portion of the bars corre- G. My construction has a furtheradvantage; that it permits of considerable abrasion before the size ofthe opening is increased, whereas as soon as any wear occurs in thestandard netting, the size of the opening is immediately increased.

Exhaust steam from the engine cylinder is led to the nozzle 5 and thenexhauste dvertically through the smoke stack 8. As the piston nears theend of its stroke a port is opened which permits the exhaust steam toescape through the nozzle 5 and out of the stack 8, thereby causing apartial vacuum at 12 which pulls the gases through the grating 7 and ifthis screening has restricted openings or offers resistance it acts as achoke to prevent the gases from coming out of the flue and in whichevent it becomes necessary to reduce the size of the nozzle opening soas to obtain a sharper draft to cause a greater pull through thescreening. This acts as a detriment on the force exerted in thecylinders by reason of the back pressure created thereby. In myconstruction I increase the total opening in the screening, or decreasethe resistance to a minimum, thereby reducing the resistance to thegases so that a sharp draft is not necessary. This means that the sizeof the nozzle can be increased giving what is called an easy exhaustwhich reduces the back pressure of the used steam in the cylinder.

In this application I have merely referred to the size of the opening inthe woven wire netting or grid, it being understood that the size of theopening is contingent upon the kind of coal used, it being generallyknown,

for instance, that lignite coal requires a much smaller maximumopeningthan bituminous coal.

The accompanying drawings illustrate the preferred form of. theinvention, though it is to be understood that the invent-ion is notlimited to the exact details of construction shown and described, as itis obviousthat various modifications thereof within the scope of theclaims will occur to persons skilled in the art.

I claim: p

1. A spark arrester for locomotive smoke boxes, comprising a pluralityof spaced apart supporting bars, a plurality of upper grid bars, aplurality of lower grid bars, the upboxes, comprising a plurality ofspacedapart substantially rectangular shaped supporting bars havingnotches arranged in the top and bottom edges thereof in alternaterelation to each other, a set of substantially rectangular shaped gridbars supported within the upper notches and having their top edgesubstani tially flush with the top edge of said support- HARRY E.GILLETTE.

per and lowergrid bars being alternately po-' sitioned with adjacentgrid bars having par' tially overlapping relationship and notchedconnections between the supporting bars and the grid bars.

2. A spark arrester for locomotive smoke boxes, comprising a pluralityof spaced apart supporting bars having notches arranged in the top andbottom edges thereof in alternate relation to each other, aset of gridbars positioned within the upper vnotches and a second set of grid barspositioned in the lower notches, the adjacent grid barshaving overlapping relationship. v

3. A spark arrester for locomotive smoke boxes, comprising a pluralityof spaced apart supporting bars having notches arranged in the top andbottom edges thereof in alternate relation to each other, a set of gridbars positioned within the upper notches and having their top edgesubstantially flush with the top edge of said supporting bars and asecond set of grid bars having notches in the top edge thereof adaptedto fit within the lower notches of the supporting bars and having theirtop edges below the top edges of the first mentioned set of grid bars.

4. A spark arrester for locomotive smoke boxes, comprising a pluralityof spaced apart supporting bars having notches arranged inv the top andbottom edges thereof in alternate relation to each other, a set of gridbars positioned within the upper notches and having their top edgessubstantially flush withthe top edge of said supporting bars, and asecond set of grid bars having notches in the top edge thereof adaptedto fit within the lower notches of the supporting bars, the bottom edgeof the first mentioned set of grid bars being positioned above thebottom edge of the said second series of grid bars.

5. A spark arrester for locomotive smoke In-testimony whereof I afix mysignature.

